In 1974 the World Health Organization (WHO) created the Expanded Program on Immunization (EPI) so that every child could get four routinely recommended vaccines — BCG, DTP, polio and measles-containing vaccine — protecting against tuberculosis, diphtheria, tetanus, pertussis, polio and measles. Since then global coverage has risen from under 5% to 85%. The Global Vaccine Action Plan 2011–2020 (GVAP), endorsed by the World Health Assembly in 2012, asks every country to reach at least 90% national coverage with all the vaccines in its schedule by 2020.
WHO and UNICEF estimate national coverage each year by reviewing all available administrative and survey data, generally counting only doses given at routine visits, not mass campaigns. The share of infants who have received their third dose of diphtheria-tetanus-pertussis vaccine (DTP3) by their first birthday is a key measure of how well a program works.
Stalled at 85%
| Vaccine | 2007 | 2010 | 2017 |
|---|---|---|---|
| DTP3 | 79% | 84% | 85% |
| First measles dose (MCV1) | 80% | 84% | 85% |
| Third polio dose (Pol3) | 81% | 84% | 85% |
- DTP3 ranged from 72% in WHO's African Region to 97% in the Western Pacific Region, and from 25% to 99% by country. 123 of 194 countries (63%) reached at least 90%, up from 117 (60%) in 2016.
- MCV1 ranged from 70% in the African Region to 97% in the Western Pacific, and from 20% to 99% by country; 118 countries (61%) met the 90% target.
Who is missed
In 2017, 19.9 million surviving infants did not get three DTP doses in their first year. Of them, 13.7 million (69%) got no DTP dose at all — the "left out" — and 6.2 million (31%) started but did not finish — the "dropped out."
From 2007 to 2017 the number of surviving infants rose by 4% (5.7 million), from 130.5 million to 136.2 million, while the number missing DTP3 fell by 7.6 million (28%), from 27.5 million to 19.9 million.
12.4 million (62%) of the children missing DTP3 lived in just 10 countries. Over 2007–2017, the number of unvaccinated children fell in the Democratic Republic of the Congo, Ethiopia, India, Indonesia and Pakistan, but held steady or rose in Afghanistan, Angola, Iraq, Nigeria and South Africa. DTP3 coverage rose in seven of the ten, fell in two and was unchanged in Nigeria, which had the most children missing DTP3 in 2017.
India and Nigeria show how differently things went. In 2007, 9.3 million children in India and 3.3 million in Nigeria did not complete DTP3. Over the decade India's eligible population fell 6% and its DTP3 coverage rose 24%, while Nigeria's eligible population grew 23% and its coverage did not change. In 2014 Nigeria overtook India, with 3.72 million children missing DTP3 against 3.65 million.
Surviving infants, and children who did not receive DTP3 by age 1, in India and Nigeria, 1997–2017. CDC.
Newer vaccines spreading
Coverage with newer and underused vaccines grew quickly between 2007 and 2017, through both better national programs and new introductions:
| Vaccine | 2007 | 2017 |
|---|---|---|
| Second measles dose (including ages 3–14) | 33% | 67% |
| Second measles dose by end of second year | 16% | 52% |
| Rotavirus, full series | 2% | 28% |
| Pneumococcal conjugate (from 2008) | 4% | 44% |
| Rubella | 26% | 52% |
| Haemophilus influenzae type b | 25% | 72% |
| Hepatitis B birth dose | 24% | 43% |
| Hepatitis B, 3 doses | 63% | 84% |
Second-dose measles coverage ranged from 25% in the African Region to 94% in the Western Pacific; 86% of countries had it in their schedules in 2017.
What it will take
Progress since 1974 is substantial, but only 63% and 61% of countries have reached the 90% target for DTP3 and MCV1. As coverage rises, gains get harder, especially above 90%, and countries that are improving need continued investment to hold their gains. In the ten countries with the most unvaccinated children, 73% (9.2 million) of those missing DTP3 had received no DTP dose at all, so much of the challenge is reaching children immunization programs have never reached. Rapid population growth may make it harder in countries where coverage has stagnated or fallen, and studying population patterns and barriers below the national level could guide targeted efforts. Focusing tailored strategies on the countries with the most unvaccinated children could have a large global impact.
The estimates have limits: coverage reporting at local levels can be inaccurate, census data can be outdated, and parents' recall can skew survey results.
Sources
Based on VanderEnde K, Gacic-Dobo M, Diallo MS, Conklin LM, Wallace AS, "Global Routine Vaccination Coverage — 2017," MMWR Vol. 67, No. 45, CDC; a work of the United States government in the public domain.
Licence: CC0 1.0 (public domain) · Adapted from www.cdc.gov
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